It is known that, in the approach phase leading to the landing of an aircraft on a runway, piloting of the latter is particularly difficult. In this approach phase, the pilot has a large quantity of information, some of which must enable him to avoid a tail or wingstrike with the ground, a hard landing or even a departure from the runway. This information principally comprises the speed of the aircraft, the slope of the aircraft and the height of the aircraft above the ground, these three items of information being displayed in the cockpit, so that the pilot can easily monitor them. Furthermore, the view of the environment gives the pilot a perception of his approach plane.
The total energy level of the aircraft, a combination of its speed and its height, is an essential parameter for estimating the risk of runway departure. However, it cannot always be estimated by the pilot. Furthermore, the energy level can be affected by the wind.